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<h3 id="1-uri&#x7F16;&#x7801;&#x65B9;&#x6CD5;-encodeuri--encodeuricomponent">1. URI&#x7F16;&#x7801;&#x65B9;&#x6CD5; encodeURI() &amp; encodeURIComponent()</h3>
<h3 id="2-eval&#x65B9;&#x6CD5;">2. eval()&#x65B9;&#x6CD5;</h3>
<h3 id="3-global&#x5BF9;&#x8C61;&#x7684;&#x5C5E;&#x6027;">3. Global&#x5BF9;&#x8C61;&#x7684;&#x5C5E;&#x6027;</h3>
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<td style="text-align:left">NaN</td>
<td style="text-align:left">&#x7279;&#x6B8A;&#x503C;NaN</td>
</tr>
<tr>
<td style="text-align:left">Infinity</td>
<td style="text-align:left">&#x7279;&#x6B8A;&#x503C;Infinity</td>
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<td style="text-align:left">Object</td>
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<tr>
<td style="text-align:left">TypeError</td>
<td style="text-align:left">&#x6784;&#x9020;&#x51FD;&#x6570;TypeError</td>
</tr>
<tr>
<td style="text-align:left">URIError</td>
<td style="text-align:left">&#x6784;&#x9020;&#x51FD;&#x6570;URIError</td>
</tr>
</tbody>
</table>
<ol>
<li>window&#x5BF9;&#x8C61;</li>
</ol>
<blockquote>
<p>&#x6D4F;&#x89C8;&#x5668;&#x90FD;&#x662F;&#x5C06;&#x5168;&#x5C40;&#x5BF9;&#x8C61;&#x4F5C;&#x4E3A;window&#x5BF9;&#x8C61;&#x7684;&#x4E00;&#x90E8;&#x5206;&#x52A0;&#x4EE5;&#x5B9E;&#x73B0;&#x7684;&#x3002;&#x56E0;&#x6B64;&#xFF0C;&#x5728;&#x5168;&#x5C40;&#x4F5C;&#x7528;&#x57DF;&#x4E2D;&#x58F0;&#x660E;&#x7684;&#x6240;&#x6709;&#x53D8;&#x91CF;&#x548C;&#x51FD;&#x6570;&#xFF0C;&#x90FD;&#x6210;&#x4E3A;window&#x5BF9;&#x8C61;&#x7684;&#x5C5E;&#x6027;&#x3002;</p>
</blockquote>
<h1 id="math-&#x5BF9;&#x8C61;">Math &#x5BF9;&#x8C61;</h1>
<h3 id="1-math&#x5BF9;&#x8C61;&#x7684;&#x5C5E;&#x6027;">1. Math&#x5BF9;&#x8C61;&#x7684;&#x5C5E;&#x6027;</h3>
<table>
<thead>
<tr>
<th style="text-align:left">&#x5C5E;&#x6027;</th>
<th style="text-align:left">&#x8BF4;&#x660E;</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align:left">Math.E</td>
<td style="text-align:left">&#x81EA;&#x7136;&#x5BF9;&#x6570;&#x7684;&#x5E95;&#x6570;&#xFF0C;&#x5373;&#x5E38;&#x91CF;e&#x7684;&#x503C;</td>
</tr>
<tr>
<td style="text-align:left">Math.LN10</td>
<td style="text-align:left">10&#x7684;&#x81EA;&#x7136;&#x5BF9;&#x6570;</td>
</tr>
<tr>
<td style="text-align:left">Math.LN2</td>
<td style="text-align:left">2&#x7684;&#x81EA;&#x7136;&#x5BF9;&#x6570;</td>
</tr>
<tr>
<td style="text-align:left">Math.LOG2E</td>
<td style="text-align:left">&#x4EE5;2&#x4E3A;&#x5E95;e&#x7684;&#x5BF9;&#x6570;</td>
</tr>
<tr>
<td style="text-align:left">Math.LOG10E</td>
<td style="text-align:left">&#x4EE5;10&#x4E3A;&#x5E95;e&#x7684;&#x5BF9;&#x6570;</td>
</tr>
<tr>
<td style="text-align:left">Math.PI</td>
<td style="text-align:left">&#x3C0;&#x7684;&#x503C;</td>
</tr>
<tr>
<td style="text-align:left">Math.SQRT1_2</td>
<td style="text-align:left">1/2&#x7684;&#x5E73;&#x65B9;&#x6839;(&#x5373;2&#x7684;&#x5E73;&#x65B9;&#x6839;&#x7684;&#x5012;&#x6570;)</td>
</tr>
<tr>
<td style="text-align:left">Math.SQRT2</td>
<td style="text-align:left">2&#x7684;&#x5E73;&#x65B9;&#x6839;</td>
</tr>
</tbody>
</table>
<pre><code class="lang-js">    <span class="hljs-comment">// 1.&#x5706;&#x5468;&#x7387;</span>
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;&#x5706;&#x5468;&#x7387;&quot;</span>,<span class="hljs-built_in">Math</span>.PI)

    <span class="hljs-comment">// 2.&#x6839;&#x53F7;2 &amp; &#x6839;&#x53F7;1/2</span>
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;&#x6839;&#x53F7;2&quot;</span>,<span class="hljs-built_in">Math</span>.SQRT2)
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;&#x6839;&#x53F7;2&quot;</span>,<span class="hljs-built_in">Math</span>.SQRT1_2)
</code></pre>
<h3 id="2-&#x6700;&#x5927;&#x503C;&#x6700;&#x5C0F;&#x503C;-max--min">2. &#x6700;&#x5927;&#x503C;/&#x6700;&#x5C0F;&#x503C; max() &amp; min()</h3>
<pre><code class="lang-js">    <span class="hljs-comment">// &#x53D6;&#x6700;&#x5927;&#x503C;</span>
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;&#x53D6;&#x6700;&#x5927;&#x503C;&quot;</span>,<span class="hljs-built_in">Math</span>.max(<span class="hljs-number">1</span>,<span class="hljs-number">22</span>,<span class="hljs-number">3</span>,<span class="hljs-number">44</span>));
    <span class="hljs-comment">// &#x53D6;&#x6700;&#x5C0F;&#x503C;</span>
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;&#x53D6;&#x6700;&#x5C0F;&#x503C;&quot;</span>,<span class="hljs-built_in">Math</span>.min(<span class="hljs-number">1</span>,<span class="hljs-number">22</span>,<span class="hljs-number">3</span>,<span class="hljs-number">44</span>));
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;&#x53D6;&#x6700;&#x5C0F;&#x503C;&quot;</span>,<span class="hljs-built_in">Math</span>.min([<span class="hljs-number">1</span>,<span class="hljs-number">22</span>,<span class="hljs-number">3</span>,<span class="hljs-number">44</span>]));<span class="hljs-comment">//NaN</span>
</code></pre>
<h3 id="3-&#x820D;&#x5165;&#x65B9;&#x6CD5;-ceil--floor--round">3. &#x820D;&#x5165;&#x65B9;&#x6CD5; ceil() &amp; floor() &amp; round()</h3>
<table>
<thead>
<tr>
<th style="text-align:left">&#x65B9;&#x6CD5;</th>
<th style="text-align:left">&#x8BF4;&#x660E;</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align:left">ceil()</td>
<td style="text-align:left">&#x5411;&#x4E0A;&#x820D;&#x5165;&#x4E3A;&#x6700;&#x63A5;&#x8FD1;&#x7684;&#x6574;&#x6570;</td>
</tr>
<tr>
<td style="text-align:left">floor()</td>
<td style="text-align:left">&#x5411;&#x4E0B;&#x820D;&#x5165;&#x4E3A;&#x6700;&#x63A5;&#x8FD1;&#x7684;&#x6574;&#x6570;</td>
</tr>
<tr>
<td style="text-align:left">round()</td>
<td style="text-align:left">&#x56DB;&#x820D;&#x4E94;&#x5165;&#x4E3A;&#x6700;&#x63A5;&#x8FD1;&#x7684;&#x6574;&#x6570;</td>
</tr>
</tbody>
</table>
<h3 id="4-&#x968F;&#x673A;&#x6570;-random">4. &#x968F;&#x673A;&#x6570; random()</h3>
<pre><code class="lang-js">    <span class="hljs-comment">// &#x968F;&#x673A;&#x6570;</span>
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;&#x968F;&#x673A;&#x6570;&quot;</span>,<span class="hljs-built_in">Math</span>.random()) ;<span class="hljs-comment">//&#x968F;&#x673A;&#x6570;&#xFF08;0,1&#xFF09;</span>
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;&#x5411;&#x4E0A;&#x53D6;&#x6574;&quot;</span>,<span class="hljs-built_in">Math</span>.ceil(<span class="hljs-number">5.01</span>));<span class="hljs-comment">//6</span>
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;&#x5411;&#x4E0B;&#x53D6;&#x6574;&quot;</span>,<span class="hljs-built_in">Math</span>.floor(<span class="hljs-number">5.99</span>));<span class="hljs-comment">//5</span>
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;&#x56DB;&#x820D;&#x4E94;&#x5165;&quot;</span>,<span class="hljs-built_in">Math</span>.round(<span class="hljs-number">5.5</span>));<span class="hljs-comment">//&#x56DB;&#x820D;&#x4E94;&#x5165;</span>
</code></pre>
<h3 id="5-&#x5176;&#x4ED6;&#x65B9;&#x6CD5;">5. &#x5176;&#x4ED6;&#x65B9;&#x6CD5;</h3>
<table>
<thead>
<tr>
<th style="text-align:left">&#x65B9;&#x6CD5;</th>
<th style="text-align:left">&#x8BF4;&#x660E;</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align:left">Math.abs(num)</td>
<td style="text-align:left">&#x8FD4;&#x56DE;num&#x7684;&#x7EDD;&#x5BF9;&#x503C;</td>
</tr>
<tr>
<td style="text-align:left">Math.exp(num)</td>
<td style="text-align:left">&#x8FD4;&#x56DE;Math.E&#x7684;num&#x6B21;&#x5E42;</td>
</tr>
<tr>
<td style="text-align:left">Math.log(num)</td>
<td style="text-align:left">&#x8FD4;&#x56DE;num&#x7684;&#x81EA;&#x7136;&#x5BF9;&#x6570;</td>
</tr>
<tr>
<td style="text-align:left">Math.pow(num&#xFF0C;power)</td>
<td style="text-align:left">&#x8FD4;&#x56DE;num&#x7684;power&#x6B21;&#x5E42;</td>
</tr>
<tr>
<td style="text-align:left">Math.sqrt(num)</td>
<td style="text-align:left">&#x8FD4;&#x56DE;num&#x7684;&#x5E73;&#x65B9;&#x6839;</td>
</tr>
<tr>
<td style="text-align:left">Math.acos(x)</td>
<td style="text-align:left">&#x8FD4;&#x56DE;x&#x7684;&#x53CD;&#x4F59;&#x5F26;&#x503C;</td>
</tr>
<tr>
<td style="text-align:left">Math.asin(x)</td>
<td style="text-align:left">&#x8FD4;&#x56DE;x&#x7684;&#x53CD;&#x6B63;&#x5F26;&#x503C;</td>
</tr>
<tr>
<td style="text-align:left">Math.atan(x)</td>
<td style="text-align:left">&#x8FD4;&#x56DE;x&#x7684;&#x53CD;&#x6B63;&#x5207;&#x503C;</td>
</tr>
<tr>
<td style="text-align:left">Math.atan2(x&#xFF0C;y)</td>
<td style="text-align:left">&#x8FD4;&#x56DE;y/x&#x7684;&#x53CD;&#x6B63;&#x5207;&#x503C;</td>
</tr>
<tr>
<td style="text-align:left">Math.cos(x)</td>
<td style="text-align:left">&#x8FD4;&#x56DE;x&#x7684;&#x4F59;&#x5F26;&#x503C;</td>
</tr>
<tr>
<td style="text-align:left">Math.sin(x)</td>
<td style="text-align:left">&#x8FD4;&#x56DE;x&#x7684;&#x6B63;&#x5F26;&#x503C;</td>
</tr>
<tr>
<td style="text-align:left">Math.tan(x)</td>
<td style="text-align:left">&#x8FD4;&#x56DE;x&#x7684;&#x6B63;&#x5207;&#x503C;</td>
</tr>
</tbody>
</table>
<pre><code class="lang-js">    <span class="hljs-comment">// &#x6B21;&#x65B9;&#x6839;</span>
    num = <span class="hljs-number">2</span>;
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;N&#x6B21;&#x65B9;&quot;</span>,<span class="hljs-built_in">Math</span>.pow(num,<span class="hljs-number">3</span>));
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;&#x5E73;&#x65B9;&#x6839;&quot;</span>,<span class="hljs-built_in">Math</span>.sqrt(<span class="hljs-number">4</span>));
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;&#x7ACB;&#x65B9;&#x6839;&quot;</span>,<span class="hljs-built_in">Math</span>.cbrt(<span class="hljs-number">27</span>));
    <span class="hljs-comment">// a&#x5E73;&#x65B9;+b&#x5E73;&#x65B9; == c&#x5E73;&#x65B9;</span>
    <span class="hljs-comment">// Math.hypot(a,b)--&gt;a&#x5E73;&#x65B9;+b&#x5E73;&#x65B9; &#x7684;&#x548C; &#x5F00;&#x6839;&#x53F7;&#xFF08;&#x53EF;&#x63A5;&#x53D7;&#x591A;&#x4E2A;&#x53C2;&#x6570;&#xFF09;</span>
    <span class="hljs-built_in">console</span>.log(<span class="hljs-built_in">Math</span>.hypot(<span class="hljs-number">3</span>,<span class="hljs-number">4</span>)==<span class="hljs-number">5</span>) 

    <span class="hljs-comment">// &#x4E09;&#x89D2;&#x51FD;&#x6570;</span>
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;&#x6B63;&#x5F26;&quot;</span>,<span class="hljs-built_in">Math</span>.sin(<span class="hljs-built_in">Math</span>.PI/<span class="hljs-number">2</span>));
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;&#x4F59;&#x5F26;&quot;</span>,<span class="hljs-built_in">Math</span>.cos(<span class="hljs-built_in">Math</span>.PI/<span class="hljs-number">2</span>));
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;&#x6B63;&#x5207;&quot;</span>,<span class="hljs-built_in">Math</span>.tan(<span class="hljs-built_in">Math</span>.PI/<span class="hljs-number">4</span>));

    <span class="hljs-comment">// &#x7EDD;&#x5BF9;&#x503C;</span>
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;&#x7EDD;&#x5BF9;&#x503C;&quot;</span>,<span class="hljs-built_in">Math</span>.abs(<span class="hljs-number">-1</span>));
</code></pre>
<p>&#x7EC3;&#x4E60;&#x9898;</p>
<pre><code class="lang-js">    <span class="hljs-comment">//&#xFF08;0,16&#xFF09; random*16</span>
    <span class="hljs-comment">// [5,16) &#xFF08;random*11&#xFF09;+5</span>
    <span class="hljs-built_in">console</span>.log(<span class="hljs-string">&quot;[5,16)&#x7684;&#x968F;&#x673A;&#x6570;&quot;</span>,<span class="hljs-built_in">Math</span>.random())
    <span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">myRandom</span>(<span class="hljs-params">min,max</span>)</span>{
        <span class="hljs-keyword">var</span> range = max - min;
        <span class="hljs-keyword">var</span> rand = (<span class="hljs-built_in">Math</span>.random()*range)+min;
        rand = <span class="hljs-built_in">Math</span>.floor(rand);
        <span class="hljs-keyword">return</span> rand;
    }
    <span class="hljs-built_in">console</span>.log(myRandom(<span class="hljs-number">5</span>,<span class="hljs-number">16</span>));

    <span class="hljs-comment">//&#x8BF7;&#x5206;&#x6790;console.log(1 + - + + + - + 1)&#x7684;&#x7ED3;&#x679C;&#x4E3A;&#x4EC0;&#x4E48;&#x7B49;&#x4E8E;2</span>
    <span class="hljs-built_in">console</span>.log (<span class="hljs-number">1</span> + - + + + - + <span class="hljs-number">1</span>)
    <span class="hljs-built_in">console</span>.log(+<span class="hljs-string">&quot;1&quot;</span>);  <span class="hljs-comment">//+&#x4F5C;&#x7528;&#x4E3A;&#x9690;&#x5F62;&#x8F6C;&#x6362;</span>

    <span class="hljs-comment">//toString.call.apply &#x6539;&#x53D8;&#x51FD;&#x6570;&#x5185;&#x90E8;&#x7684;&#x6307;&#x5411;</span>
    <span class="hljs-built_in">console</span>.log(<span class="hljs-built_in">Math</span>.max.apply(<span class="hljs-literal">null</span>, [<span class="hljs-number">1</span>,<span class="hljs-number">2</span>,<span class="hljs-number">3</span>,<span class="hljs-number">4</span>])) <span class="hljs-comment">//Math.max(1,2,3,4)</span>
</code></pre>

                                
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